NEW ORLEANS, May 27  Representative William J. Jefferson has always
liked to talk about growing up in an impoverished farm community,
picking cotton for $3 a day and hitting the books hard enough to win
his ticket out  a scholarship to Harvard Law School.

But even as Mr. Jefferson built a reputation as one of Louisiana's
brightest, most effective leaders, a less flattering view began to
emerge, one signified by his nickname in political circles, "Dollar Bill."

Early in his career, as a state legislator, he was criticized for
enriching his law firm with contracts from state and local agencies.
He also ran stores that rented appliances by the month to poor
residents, owned dilapidated apartment buildings and was sued by
federal regulators over a defaulted loan.

Now, with the Federal Bureau of Investigation raid on his Capitol Hill
office on May 20, Mr. Jefferson, a 59-year-old Democrat, is under
investigation for possibly turning his efforts to promote trade with
Africa into another sideline worth hundreds of thousands of dollars 
and has become the central figure in a political drama consuming
Washington.

The unprecedented raid has set off a huge institutional showdown, with
Republican leaders including J. Dennis Hastert of Illinois, the
speaker of the House, challenging the White House and criticizing the
F.B.I.'s actions. Democratic leaders have also stood by the speaker's
side.

President Bush has stepped into the fray, ordering the F.B.I. to seal
any records it seized and calling for a 45-day cooling-off period to
allow time to resolve the crisis.

The raid on Mr. Jefferson's office took place barely a week ago. But
in a sense, the questions circling him have long resonances in his
career, which was shaped by a remarkable ascent from the deepest
poverty and a quest for the comforts his family never had.

In a 95-page affidavit released after the raid, the F.B.I. accused Mr.
Jefferson, an eight-term lawmaker, of demanding more than $400,000 in
bribes to help iGate Inc., a technology company based in Kentucky,
obtain lucrative contracts in Africa. The bureau said it had also
videotaped him accepting a suitcase with $100,000 in cash and later
found $90,000 of it in his freezer.

Though the details were blacked out, the affidavit also said the
F.B.I. had "evidence linking Congressman Jefferson to at least seven
other schemes" in which he "sought things of value in return for his
performance of official acts."

Mr. Jefferson has vigorously denied wrongdoing and has not been
charged with a crime. "I certainly did not sell my office," Mr.
Jefferson said in a recent statement. "The government seems inclined
to view the facts in the worst possible light, and to characterize
events that could be explained, or are exculpatory, in ways that tend
to incriminate."

Whether his actions were criminal or not, several people who have long
known Mr. Jefferson said he had often seemed driven by a desire to
escape his spartan roots.

"There was always a feeling among those who knew him as Dollar Bill
that having grown up as poor as he did, his hunger for wealth always
burned," said Allan Katz, a New Orleans political consultant.

Mr. Jefferson, a taciturn man who began his career as a favorite of
good-government groups, has built a political empire in New Orleans,
winning re-election by wide margins and helping his sister, one of his
five daughters and many allies win public offices.

Standing outside a new post office that Mr. Jefferson helped bring to
his district, one voter, Joyce F. Smith, said that if the accusations
were true, "I'd be very disappointed because he's been a very good
congressman."

But many people here have been joking about his "frozen assets" and
"cold cash." And Ms. Smith added, it is "hard for me to believe" that
he would have stashed legitimate earnings in frozen-food containers
and aluminum foil.

Mr. Jefferson was raised, along with eight brothers and sisters, on a
small farm in northeast Louisiana, where, he said earlier this year,
"our whole life revolved around that cotton field." His father left
school after second grade, and his mother attended only through eighth
grade.

As a child, Mr. Jefferson was such a good shot, his father once said,
that when it came time to bag dinner, "if I wanted one rabbit, I'd
give him one shell; and if I needed two rabbits, I'd give him two."

After he graduated from Southern University in Baton Rouge in 1969,
Mr. Jefferson has said, he won his mother's blessing to go to Harvard
Law School  she had never heard of it  only by explaining that it
had been John F. Kennedy's college.

Mr. Jefferson has credited his parents with pressing the value of hard
work. Elizabeth Brannum Trass, one of his high school teachers, said
in an interview that he had always had the seriousness of purpose that
helped catapult him onto a much faster track.

A clerkship with a United States district judge brought Mr. Jefferson
to New Orleans in 1972. He got into politics as a campaign aide for
Ernest N. Morial, who became the city's first black mayor in 1978 and
gave Mr. Jefferson the Dollar Bill nickname.

Friends of both men said the mayor thought Mr. Jefferson had tried too
aggressively to collect legal fees for helping Mr. Morial win the
election. But after Mr. Jefferson became a state senator in 1979, his
political rivals began to use "Dollar Bill" to refer to his expanding
financial ventures.

His rental business  which leased television sets and other
appliances to people who could not afford to buy them  appeared on
the delinquent list in a city sales-tax scandal in the 1980's. And a
day after he was elected to Congress in 1990, the Resolution Trust
Corporation, which was trying to clean up the mess from the collapse
of savings institutions, sued him for $160,000 over an
apartment-building loan on which he had quit making payments. He later
settled the suit, with friends saying his investments had been hurt by
a faltering economy.

Still, once Mr. Jefferson became a close ally of President Bill
Clinton, and then won a seat on the powerful House Ways and Means
Committee, he was able to provide "absolute A+" support for city
projects, said Marc H. Morial, one of Ernest Morial's sons and the
mayor of New Orleans from 1994 to 2002.

Mr. Jefferson also became known as a strong advocate of freer trade
and made at least nine trips to Africa to promote it, including one
with President Clinton. He championed a 2000 law that extended trade
benefits to sub-Saharan Africa. "Africa is a reservoir of
opportunities for American businesses," he said then.

Over the years, Mr. Jefferson has received campaign contributions and
free travel from individuals and companies seeking business in Africa,
including iGate.

Campaign finance records show he received a $1,000 contribution as
early as 2001 from Vernon L. Jackson, the chief executive of iGate,
which makes technology to transmit high-speed Internet service across
the wires used in some African nations. Mr. Jackson pleaded guilty
this month to bribing Mr. Jefferson with more than $400,000 in cash
and millions of shares of iGate stock.

Government documents show that Mr. Jackson told the F.B.I. that when
he met Mr. Jefferson in late 2000, the congressman voluntarily helped
promote iGate's products  a normal and legitimate action for a
government official involved in trade issues. But according to the
F.B.I. documents, in early 2001, the congressman's actions became
improper when he said he would continue to use his influence on
iGate's behalf only if Mr. Jackson made payments to a company, the ANJ
Group, run by the Jefferson family. The iGate payments were disguised
as consulting fees, the F.B.I. said.

Mr. Jefferson says these were private business dealings that had
nothing to do with his work on the House committee.

But as part of a 2003 deal to distribute iGate's products, a Nigerian
company, Netlink Digital Television, agreed to pay the congressman $5
per subscriber, the F.B.I. affidavit said, "in return for Jefferson's
official assistance if the deal was successful."

House records show that in February 2004, Mr. Jefferson led a business
delegation to Nigeria and Cameroon as a co-chairman of the
Congressional Nigeria Caucus and the Africa Trade and Investment
Caucus. The trip, which cost $16,313, according to the records, was
paid for in part by iGate.

In 2005, the F.B.I. said, Mr. Jefferson wrote to the vice presidents
of Nigeria and Ghana, and traveled to Ghana, seeking approval for
iGate projects. Within a week after returning, the F.B.I. said, Mr.
Jefferson used his influence to help a Virginia woman, Lori Modi, who
had invested $3.5 million in the Nigeria project. He introduced her to
officials at the Export-Import Bank of the United States and urged
them to provide financing for the project.

But by then, Ms. Modi had asked the F.B.I. to investigate the deal.

Investigators said that in negotiating the deals, Mr. Jefferson had
often cited his desire to provide for his five daughters, three of
whom also have degrees from Harvard Law School.

From December 2004 through June 2005, the F.B.I. said in its
affidavit, Mr. Jefferson increased his demands for equity in one
Nigerian company, to 30 percent, to be split among his daughters. He
also told an investor that one of his daughters had to be retained to
do legal work, according to documents in the case.

Then, on July 30, 2005, when Mr. Jefferson met Ms. Modi at a
Ritz-Carlton hotel, the F.B.I. said it supplied her with a briefcase
with $100,000 in marked bills. Mr. Jefferson had told her the money
would be needed to bribe Nigerian officials, the affidavit said.

As the F.B.I.'s video cameras zoomed in on him, the bureau said, Mr.
Jefferson drove off with the briefcase on the seat of his Lincoln Town
Car. And when agents raided his home four days later, $90,000 of the
money turned up again, in the kitchen freezer.

Christopher Drew reported from New Orleans for this article, and
Robert Pear from Washington. Adam Nossiter contributed reporting from
New Orleans.

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